Method and apparatus for crushing nonconductive materials

ABSTRACT

A method of crushing or smashing nonconductive materials such as natural ore materials and concretes by a discharge voltage requires a large amount of energy for crushing or smashing. Products produced by crushing or smashing have not been recycled effectively as new nonconductive raw materials. A value set by the quality and a thickness of the nonconductive materials to be crushed, an impulse voltage Uo, a time constant τ and a spark constant A is defined as a parameter P of an electric circuit. By setting the value of P to 0.02≦P≦1.0 to cause crushing, energy stored in the circuit can be utilized effectively. Accordingly, uniformcrushedor smashed matter with high quality can be manufactured effectively.

TECHNICAL FIELD

The present invention relates to a method and an apparatus for crushingor smashing nonconductive materials containing conductive materials suchas natural nonconductive ore materials such as quartzites, granites,rocks and the like or waste ferro-concretes or resin molded productscontaining metal reinforcements to be able to be recycled as new rawnonconductive materials.

BACKGROUND TECHNIQUE

A method of processing nonconductive materials such as ferro-concretescontaining conductive materials such as reinforcements and recycling theprocessed materials to manufacture new nonconductive materials is knownas described in A. F. Usov, B. V. Siomkin and N. T. Zinovyev,"TRANSITIONAL PROCESSES IN THE PLANTS USING IMPULSE TECHNOLOGIES"(Leningrad: Nauka, 1987), page 189. In this method, wasteferro-concretes are placed in the water, are crushed by electricdischarge and further smashed to pieces. Ferro reinforcements areremoved from the smashed waste ferro-concretes, and water containing thesmashed pieces of concrete, which was used in crushing or smashing ofnonconductive materials, is removed by a pump. New ferro-concretes aremanufactured using the pieces as raw materials.

In the above method, however, a very large amount of energy is requiredto crush the ferro-concretes. As a result, all of the ferro-concretesare no crushed and recycled, so that the amount of recycledferro-concretes is reduced.

The above defect is partially solved by the method described in page 96of "RECYCLING OF CONCRETES" (Moscow, Stroyiztat, 1988) by B. V. Gusevand V. A. Zagurskiy. According to this method, waste ferro-concretes arepreliminarily crushed by a crushing machine and ferro reinforcements arethen removed from the crushed waste ferro-concretes and melted. Afterthe crushed concrete is further smashed to pieces, the crushed concreteis classified by size and kind of pieces. The classified pieces ofconcrete are mixed to manufacture a new mixture of concrete.

In the above method, however, the optimum amount of the electro impulseand electric-physical properties of crushed concrete is not considered.Accordingly, there is the problem that a voltage required for crushingof concrete cannot be adjusted, so that concretes cannot be crushed withan efficient use of energy. Further, all of the processed products suchas crushed and smashed concrete materials and ferro reinforcementscannot be recycled as raw materials of new concrete and the problem thatthe amount of recycled waste ferro-concretes is low is not solved.

It is an object of the present invention to solve the above problems inthe prior art by providing a method or an apparatus for crushing orsmashing nonconductive materials such as waste ferro-concretes withreduced consumption of energy and capable of recycling almost all of thecrushed or smashed non-conductive materials to produce new nonconductiveraw materials.

DISCLOSURE OF THE INVENTION

According to the present invention, in the method of crushing orsmashing nonconductive materials by electric discharge impulse, when aparameter of an electric circuit for applying a discharge voltage isdefined as P, electric discharge is made when a value of the parameter Pis within a range of 0.02≦P≦1.0.

The parameter P is expressed by the following equation 1, where lrepresents a thickness of nonconductive materials, Uo a impulse voltageapplied to the nonconductive materials, and τ a time constant. Further,A represents a spark constant, which is proportional to a sum total ofcurrents flowing when the impulse voltage is applied to thenonconductive materials and a resistance value and is inverselyproportional to the thickness l. ##EQU1##

The nonconductive materials may contain conductive materials. In thiscase, the conductive materials function as ground and when thenonconductive materials are crushed or smashed, the conductive materialscan be taken out while they maintain their original shape or quality.

The nonconductive materials of the present invention includes naturalore materials, concretes, resin products, rubber products and the like.Further, the conductive materials include ferro reinforcements or carbonfibers contained in the concretes, metal fillers contained in the resinproducts, metal materials contained in the rubber products and the like.

Further, nonconductive materials are put into a container filled withliquid and a high-voltage electrode for applying a voltage abuts againstthe nonconductive materials to thereby apply electric discharge to thenonconductive materials while using the liquid or container as ground.

According to the present invention, in the crushing apparatus ofnonconductive materials including an installation member of thenonconductive materials, high-voltage electrodes for applying a highvoltage to the nonconductive materials, and an electric circuit forapplying a discharge voltage to the high-voltage electrodes, when aparameter of the electric circuit for supplying a discharge voltage isdefined as P, electric discharge is made within a range of 0.02≦P≦1.0;

The parameter P is expressed by the equation 1, where l represents athickness of each of the nonconductive materials, Uo a impulse voltageapplied to nonconductive materials, and τ a time constant. Further, "A"represents a spark constant, which is proportional to a sum total ofcurrents flowing when the impulse voltage is applied to thenonconductive materials and a resistance value and is inverselyproportional to the thickness l.

With the above structure, nonconductive materials containing conductivematerials can be crushed or smashed.

Further, nonconductive materials are put in a container filled withliquid and the high-voltage electrode for applying a voltage can abutagainst the nonconductive materials to give electric discharge to thenonconductive materials using the liquid or container as ground.

The container can be structured to includes a bottom plate having aporous structure through which crushed or smashed nonconductivematerials can drop and an opening and closing gate for taking out thematerials dropped from the bottom plate, to thereby separate conductivematerials from crushed or smashed nonconductive materials.

In addition, a plurality of the containers are arranged in a cascademanner and nonconductive materials crushed in a first container aresuccessively moved into a container at a next-stage for crushing orsmashing again, so that nonconductive materials can be crushedcompletely.

For example, as shown in FIG. 2, the electric circuit for applying thedischarge voltage desirably comprises a series/parallel conversioncircuit of condensers, generation members for generating a high-voltage,impulse generator comprising discharge spheres or discharge electrodesdisposed opposite to each other separate from each other by apredetermined distance, a plurality of condensers connected in parallelto one another before discharge occurs in the discharge spheres ordischarge electrodes and connected in series to one another whendischarge occurs in the discharge spheres or discharge electrodes, andinductance elements connecting between the condensers when thecondensers are connected in parallel to one another.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic diagram illustrating a crushing method andapparatus of non-conductive materials and a recycling and manufacturingapparatus of crushed materials according to the present invention;

FIG. 2 is a circuit diagram of an electric circuit for supplyingdischarge energy to high-voltage electrodes for crushing or smashingnonconductive materials in the present invention;

FIG. 3 is an equivalent circuit diagram of the circuit shown in FIG. 2;

FIG. 4 is a graph showing the relation of electric power u(t) and i(t)and time t in the equivalent circuit shown in FIG. 3;

FIG. 5 is a graph showing the relation of the numbers t/(LC)^(1/2) andN(t)/No of no dimension in the time system with respect to differentvalues of P; and

FIG. 6 is a graph showing the relation of P and a maximum value f ofN(t)/No.

BEST MODE FOR CARRYING OUT THE INVENTION

Before explaining an embodiment of the present invention, a parameter Pof an electric circuit defined by the Inventors in the present inventionis now described.

P is a parameter of an electric circuit for supplying discharge energyfor crushing or smashing nonconductive materials represented by concretein the present invention and is the number of no dimension expressed bythe equation 1.

In the equation 1, "A" represents a spark constant defined by theInventor and related when electric impulse is applied to nonconductivematerials such as concrete. "l" represents a thickness in meters of eachof the nonconductive materials such as, for example, concretes, "Uo"represents a impulse voltage in kV (kilovolt) of the electric circuitand "τ" represents a time constant in s (second) in the electriccircuit.

The time constant τ is determined by an inductance and a capacitance ofthe whole circuit shown in FIGS. 2 and 3 and is expressedby thefollowing equation.

(Equation 2)

    τ=√LC

In the equation 2, L represents an inductance in H (henry) of the wholecircuit, and C represents a capacitance in F (farad) in the circuit.

In the equation 1, "A" represents an integral constant named as a sparkconstant. When a current i (ampere) flows in nonconductive materialshaving a thickness of l (m) in response to a fixed high voltage Uo (V)in a short time t (second) and an electric resistance of each of thenonconductive materials is R (ohm), the relation shown by the followingequation 3 is effected among them.

(Equation 3)

    R=Al(∫.sub.0.sup.t i.sup.2 dt).sup.-1/2

"A" functions as a constant for equalizing the left side to the rightside of the equation 3 and is expressed by the dimension of unit(V·sec^(1/2) ·m⁻¹) from the relation of the left side and the right sideof the equation 3. In the present invention, the constant A expressed bythis dimension is named the spark constant. Further, the constant A canbe expressed by the following equation 4 from the equation 3. ##EQU2##

The equations 3 and 4 can be understood easily by comparing theequations with the Ohm's law (R=voltage/current). In the presentinvention, nonconductive materials such as concretes are crushed orsmashed by electric discharge impulse, while when a discharge voltage isapplied to the nonconductive materials actually, an electricalresistance value of concretes or the like cannot be expressedquantitatively. Thus, when a discharge voltage is applied to concretehaving a thickness of l, an integrated value of variation of a currentflowing in a short time t by time is defined as a current value flowingthrough concrete having the thickness of l and a product of theintegration constant A and l is replaced by a voltage in the Ohm's law.

Accordingly, by applying a high-voltage pulse to nonconductive materialssuch as concretes actually to measure a current i flowing through theelectrode and calculating a resistance R of each of the nonconductivematerials from a capacitance and an inductance in the circuit appliedwith a discharge voltage, the voltage and the current i, the sparkconstant A can be obtained experimentally from the current, theresistance R and the thickness l each of the nonconductive materials.The spark constant A is an inherent value in accordance with each of thenonconductive materials. Further, a spark constant A of, for example,waste ferro-concretes or resin molded product containing metal fillersor rubber products containing metal materials has an inherent value inaccordance with a combination of conductive materials such asreinforcing rods, metal fillers or metal materials and nonconductivematerials such as concretes, resins and rubbers (considering a mixedratio thereof).

In the present invention, when nonconductive materials such as concretesare crushed or smashed by electric discharge impulse, circuit valuessuch as a impulse voltage Uo applied from the electric circuit shown inFIG. 2 and the like, an inductance L and a capacitance C are varied orare selected to be proper values in accordance with a value of theresistance R of each of the nonconductive materials calculated by theequation 3 to thereby crush or smash the nonconductive materials witheffective energy. The parameter P is set with the relation of theresistance R, the thickness l, the spark constant A and the timeconstant τ, and a range of the parameter P that nonconductive materialscan be crushed or smashed with most effective energy use is to becalculated.

More particularly, the parameter P which is a constant of no dimensionis set to examine the interrelation of the spark constant A, thethickness l of each of the nonconductive materials, the impulse voltageUo and the time constant τ (inductance L and capacitance C) in the wholecircuit by an experiment and vary them. Attention is paid to the factthat circumstances upon crushing or smashing of nonconductive materialscan be set to be identical when a value of P is the same even if valuesof the variables A, l, Uo, τ (L, C) are varied.

For example, it is first assumed that the parameter of the circuit is P₁when the variables are A₁, l₁, Uo₁ and τ₁ (L₁ and C₁) and the parameteris P₂ when the variables are A₂, l₂, Uo₂ and τ₂ (L₂ and C₂). At the timewhen P₁ =P₂, the crushing conditions are identical.

When nonconductive materials such as, for example, ferro-concretes arecrushed or smashed by electric discharge impulse, it is desirable tochange the impulse voltage Uo, the inductance L and the capacitance C inaccordance with a value of the resistance R of the ferro-concretes tochange a value of the parameter P in order to crush or smash theferro-concretes effectively. In the present invention, by setting avalue of P upon crushing of nonconductive materials to 0.2≦P≦1.0, energystored in the electric circuit is utilized effectively to crushnonconductive materials.

A structure of the present invention is now described with reference tothe accompanying drawings. FIG. 1 illustrates a crushing method andapparatus of nonconductive materials and a recycling and manufacturingapparatus of crushed materials according to the present invention.

In FIG. 1, numeral 1 denotes a first container and numeral 2 denoteswaste ferro-concrete, for example, as nonconductive material, and in theembodiment the waste ferro-concrete 2 is matter to be crushed byelectric discharge impulse. Numeral 3 denotes a first high-voltageelectrode, 4a a bottom plate having a porous structure, 4b an openingand closing gate, 5 a second container, 6 a second high-voltageelectrode, 7a a bottom plate having a porous structure, 7b an openingand closing gate, 8 a classifying apparatus, 9 filler storageapparatuses, 10 a mixing apparatus for concrete, and 11 a pouring mold.In the embodiment shown in FIG. 1, two high-voltage electrodes areprovided, although crushing or smashing may be made by only onehigh-voltage electrode. Further, three or more high-voltage electrodesmay be used to crush or smash nonconductive materials.

The above apparatus is used as follows. The waste ferro-concrete 2constituting the matter to be crushed is put into the first container 1filled with water and the first high-voltage electrode 3 is disposedabove the ferro-concrete. The first and second high-voltage electrodes 3and 6 are connected to the circuit shown in FIG. 2 through a terminal Tand a high-voltage impulse is supplied thereto from the electriccircuit. Ferro reinforcements contained in the waste ferro-concrete 2,the first container and water in the first container are utilized asground. Impulse force by electric discharge is applied to the wasteferro-concrete 2 from the first high-voltage electrode 3 to therebycrush the waste ferro-concrete 2. After the waste ferro-concrete 2 iscrushed, ferro reinforcements are exposed. The ferro reinforcements arerecycled as materials for newly manufactured ferro-concrete. The bottomplate 4a of the porous structure is moved vertically or horizontally tothereby drop crushed or smashed pieces of concrete into a lower chamberso that the pieces are separated from the ferro reinforcement. Thecrushed pieces of concrete are removed from the opening and closing gate4b and water containing the pieces is removed. Then, the crushed piecesare conveyed to the second container 5. The conveyance of the crushedpieces of concrete from the first container 1 to the second container 5may be made by a belt conveyer, for example.

Water is put into the second container 5 and the crushed pieces ofconcrete are finely smashed by electric impulse force from the secondhigh-voltage electrode 6. The finely smashed concrete pieces are droppedthrough the bottom plate 7a of the porous structure and are taken outfrom the opening and closing gate 7b. The removed concrete pieces areclassified minutely by the classifying apparatus 8 and are then put intothe filler storage apparatuses 9.

Water exhausted from the first and second containers 1 and 5 is fed intothe mixing apparatus 10. Further, crushed pieces of concrete in thesecond container 5 are also fed from the filler storage apparatus 9 tothe mixing apparatus 10. Adequate volume of concrete and water havingthe proper composition are mixed in the mixing apparatus 10 to produceconcrete mixture. Then, the concrete mixture and the ferroreinforcements taken out by the crushing of the waste ferro-concrete 2are put into the pouring mold 11 to manufacture new ferro-concrete. Whenthe concrete mixture is manufactured, unused filler can be added to theconcrete powder obtained from the waste ferro-concrete 2 to therebymanufacture ferro-concrete of good quality.

FIG. 2 is a schematic diagram illustrating the electric circuit forsupplying a impulse voltage to the first and second high-voltageelectrodes 3 and 6.

As shown in FIG. 2, the first high-voltage electrode 3 is connected tothe electric circuit through a terminal T. Although not shown, thesecond high-voltage electrode is also connected to the electric circuitin the same manner. The electric circuit shown in FIG. 2 includes avoltage regulator 12, a high-voltage transformer 13 and a impulsegenerator 14. The impulse generator 14 includes circuits 14A . . . ,which are connected in parallel to one another, and each of the circuits14A includes condensers 14a, inductances 14b and discharge spheres (ordischarge electrodes) 14c.

Operation of the electric circuit shown in FIG. 2 is now described.First, a voltage is applied to the voltage regulator 12 and the voltageis transformed to a high voltage by the high-voltage transformer 13.When a voltage, of, for example, 440 V is applied to the voltageregulator 12, the voltage is transformed to a high voltage of (10-50) kVby the high-voltage transformer 13. The representation (10-50) means"greater than or equal to 10 and less than or equal to 50" andhereinafter the same representation is used with the same meaning.

The voltage transformed by the high-voltage transformer 13 is suppliedto the circuits 14A . . . and energy is stored in the condensers 14a . .. . At this time, since the circuits 14A, . . . are not connected by thedischarge spheres 14c, the condensers 14a . . . are connected inparallel and the same electric charges are applied to all of thecondensers 14a . . . . When high energy is stored in the condensers 14a. . . and a predetermined voltage is reached, discharge occurs betweenthe adjacent discharge spheres 14c and 14c and resistances of thecircuits 14A . . . are reduced to 0, so that the circuits 14A . . . ,that is, the condensers are connected in series.

The voltage at this time depends on a distance between the dischargespheres 14c and the distance can be adjusted to thereby set the voltageto a predetermined electric charge value. The impulse voltage Uo isapplied to the first and second high-voltage electrodes 3 and 6 from theseries connected impulse generators 14, so that discharge occurs in thewaste ferro-concrete 2. The energy W (Joule) stored in the impulsegenerator 14 can be expressed by the following equation 5. ##EQU3##

Further, representative electric power No (watt) stored in the electriccircuit can be expressed by the following equation 6 by dividing theenergy W by a time constant τ. ##EQU4##

FIG. 3 is an equivalent circuit diagram of the whole circuit containingthe impulse generator 14 shown in FIG. 2 and the waste ferro-concrete 2constituting the matter to be crushed. When a voltage of the circuit isu(t) and a current flowing in the circuit is i(t), the relation by thetime of the voltage u(t) and the current i(t) with respect to time t isshown in FIG. 4. The equivalent circuit is represented by a general RCLcircuit and resistance R is a resistance component of the wasteferro-concrete 2. The resistance R is to be defined by the equation 3.

Further, electric power N(t) (consumption power in case of theresistance is R) where the circuit at time t can be represented by aproduct of the voltage u(t) and the current i(t) as shown in thefollowing equation 7.

(Equation 7)

    N(t)=i(t)×u(t)

In the present invention, the value of the parameter P of the electriccircuit has been set as a result that the crushing apparatus ofnonconductive materials of the present invention shown in FIGS. 1 and 2was used to perform an actual process by means of a processing methoddescribed below.

As the nonconductive materials, concretes of the Russian Gost standard200, 300, 400 and 500, quartzite and granite were used. The sparkconstants A of the concrete, the quartzite and the granite are shown inTable 1.

                  TABLE 1                                                         ______________________________________                                        Russian Gost Standard                                                         of Concrete             Granite quartzite                                     ______________________________________                                                200    300    400   500  600                                          A,      290    305    325   350  375  600   800                               (V.sub.s.sup.1/2 m.sup.-m)                                                    ______________________________________                                    

The spark constant A of each concretes in Table 1 can be calculated fromthe equation 4 by applying the high impulse voltage Uo to concretematerials having a predetermined thickness l, calculating a currentflowing in the electrode applied with the impulse voltage Uo andcalculating the resistance R of concrete in consideration of the impulsevoltage Uo, the current, the capacitance C and the inductance L of thecircuit for applying the impulse voltage Uo.

The ranges of values Uo, C and L of the electric circuit used when thematter to be crushed such as the concrete and natural rock is crushedare shown below.

Uo=(120-600) kV

C=(0.016-0.225) μF

L=(10-830) μH

τ=(0.4-13.6) μS

These values can be varied to set the parameter P to a value suitablefor crushing of material having not only different Gost or sparkconstant A but also different thicknesses l.

FIG. 4 shows variation of the current i(t) and the voltage u(t) withrespect to time t of the equivalent circuit shown in FIG. 3. FIG. 4shows that there is a time difference between the time that the currenti(t) is a maximum value i_(o) and the time that the voltage u(t) is amaximum value u_(o) when the impulse voltage Uo is applied tononconductive material, for example, concrete.

FIG. 5 is a graph showing the relation of t/(LC)^(1/2) and N(t)/No withrespect to each value of the parameters P of the electric circuit whichare set to 0.02, 0.2, 0.4, 0.6, 0.8 and 1.0 when the matters to becrushed shown in Table 1 are crushed or smashed. The abscissa representst/(LC)^(1/2), that is, the number of no dimension in the time system andthe ordinate represents N(t)/No, that is, electric power consumed in theresistance R to electric power stored in the electric circuit. Theincreased N(t)/No means that electric power consumed in the first orsecond high-voltage electrode 3 or 6 is increased and force for crushingor smashing concrete and the natural rock is large.

When P=0.02 and P=1.0, the maximum value of N(t)/No does not reach 0.1.On the contrary, when P=0.4, the maximum value of N(t)/No is maximum,which is N(t)/No=0.275 at t/(LC)^(1/2) =1.5. When the value of P exceeds1, the time required for discharge is made long and the conductiveefficiency is remarkably reduced. When the values of Uo, C, L and Trelative to the electric circuit are such that the value of P is withinthe above ranges, the crushing phenomenon does not occur. When P is lessthan 0.02, the discharge time is extremely short and the efficiency ofelectric power is also remarkably reduced in this case. When the valuesrelative to the electric circuit are such that the value of P is withinthe above ranges, crushing does not occur. The efficiency of energy useis maximum when P=0.4.

FIG. 6 is a graph showing the relation of the parameter P and a maximumvalue f=N_(max) /No of N (t) /No from the graph shown in FIG. 5.

N_(max) is the maximum value of N(t) and f is maximum when N_(max) =No.That is, the maximum value of f is f=1. When the value of f is large,electric power consumed in the first high-voltage electrode 3 isincreased and the crushing energy for nonconductive material such asconcrete and natural ore material is large.

In FIG. 6, when P is smaller than or equal to 0.02 or larger than orequal to 1.0, f is a value substantially close to 0. That is, when P issmaller than or equal to 0.02 or larger than or equal to 1.0, N_(max) isvery small as compared with No and energy consumed to crush concrete issmall. Accordingly, when P is smaller than or equal to 0.02 or largerthan or equal to 1.0, matters to be crushed are not crushed. Further,when P is 0.02≦P≦1.0, the value of f is larger than or equal to 0 andwhen P=0.4 the value of f is maximum. Accordingly, in the presentinvention, the value of P upon crushing of concrete is 0.02≦P≦1 anddesirably P=0.4.

Next, differently from the experiment, the energy efficiency η₁ in thecase where the crushing method of the present invention is used wascalculated from the equation described below. The following equations 8to 10 are defined by the inventions of the present invention.

The equation for calculating the energy efficiency η₁ is the followingequation 8.

(Equation 8)

    η.sub.1 =2.82×P×y.sub.max ×τ.sub.1.sup.1/2

y_(max) of the equation 8 is calculated by the following equation 9.##EQU5##

Further, τ₁ of the equation 8 is calculated by the following equation10. ##EQU6##

As described above, the energy efficiency η₁ depends on the value of theparameter P of the electric circuit.

For example, when P=0.4, the energy efficiency η₁ is calculated to be56.7% by the above equations 8, 9 and 10. Accordingly, when P=0.4,concrete is crushed while the energy (electric power) stored in thecircuit is reduced by 56.7%.

Next, the energy efficiency η₁ in the case where concrete of the Goststandard 200 and having a thickness of 0.1 m was crushed on condition ofUo=357 kV, C=0.09 μF and L=150 μH was calculated. Since the sparkconstant A of the concrete of the Gost standard 200 is 290 V·s^(1/2)·m⁻¹ from Table 1, the parameter P is P=0.0419 from the equation 1.Accordingly, the energy efficiency at this time is 11.4% from theequations 8, 9 and 10. In other words, concrete can be crushed whileelectric power stored in the electric circuit shown in FIG. 2 is reducedby 11.4%, while the energy efficiency η₁ at this time is smaller thanthat for P=0.4.

Further, a thickness of concrete of the Gost standard 200 is set to 0.01m and the concrete was crushed on the same condition of the electriccircuit. The parameter P of the electric circuit at this time is 0.0042.The energy efficiency is calculated as 1.2% by the equations 8, 9 and 10and it is understood that the energy efficiency is deteriorated. Thesevalues are very near values to experimental values.

INDUSTRIAL AVAILABILITY

According to the present invention described above in detail, whennonconductive materials such as natural ore materials, concretes, resinor rubber are crushed or smashed by discharge voltage, the parameter ofthe electric circuit for supplying the discharge voltage is defined as Pand the value of P can be set to the reference to thereby utilizeelectric power stored in the electric circuit effectively.

Further, when conductive reinforcements are contained in nonconductivematerials, the reinforcements function as ground and only thenonconductive materials are crushed or smashed. Accordingly, theconductive reinforcements can be taken out while being containedtherein.

In addition, since almost all of processed matters produced by crushingor smashing can be recycled in accordance with a purpose, newnonconductive materials can be produced in accordance with the object ofthe present invention inexpensively without production of waste matters.

We claim:
 1. A method for crushing or smashing nonconductive materialsby electric discharge impulse, comprising;setting parameters of anelectric discharge circuit for supplying a discharge voltage tononconductive materials such that P as expressed by the followingequation is within a range of 0.02≦P≦1.0; ##EQU7## where said parametersof said electric discharge circuit comprise l which is a thickness ofsaid nonconductive materials, U₀ an impulse voltage applied to saidnonconductive materials, τ which is a time constant, and A which is aspark constant which is proportional to a sum total of currents flowingwhen said impulse voltage is applied to said nonconducive materials anda resistance and is inversely proportional to said thickness l; andapplying said electric discharge impulse from said electric dischargecircuit to said nonconductive materials.
 2. A crushing method fornonconductive materials according to claim 1, wherein conductivematerials are mixed in with said nonconductive materials.
 3. A crushingmethod for nonconductive materials according to claim 1 or 2, furthercomprising putting said nonconductive materials (2) in a container (1),(5), filling said container (1), (5) with liquid and placinghigh-voltage electrodes (3), (6) in contact with said nonconductivematerials for applying said electric discharge impulse to saidnonconductive materials (2) to produce electric discharge while usingsaid liquid or container (1), (5) as ground.
 4. A crushing apparatus fornonconductive materials comprising a container for nonconductivematerials, high-voltage electrodes (3), (6) for applying a high voltageto said nonconductive materials abutting against said nonconductivematerials, and an electric circuit for applying a discharge voltage tosaid high-voltage electrodes (3), (6), wherein when a parameter of saidelectric circuit for applying said discharge voltage is defined as Pexpressed by the following equation, electric discharge is made within arange of 0.02≦P≦1.0; ##EQU8## where l represents a thickness of each ofsaid nonconductive materials, U₀ an impulse voltage applied to saidnonconductive materials, τ a time constant, and A a spark constant whichis proportional to a sum total of currents flowing when said impulsevoltage is applied to said nonconductive materials and a resistance andis inversely proportional to said thickness l; anda liquid provided incontainer (1), (5) to produce electric discharge while using said liquidor container (1), (5) as ground; and wherein said container (1), (5)includes a bottom plate (4a), (7a) having a porous structure throughwhich crushed or smashed nonconductive materials (2) are dropped and anopening and a closing gate (4b), (7b) for taking out said crushed orsmashed materials is dropped from said bottom plate.
 5. A crushingapparatus for nonconductive materials according to claim 4, wherein aplurality of said containers are arranged in a cascade manner andnonconductive material(s) (2) crushed in a first container (1) issuccessively moved into a container (5) at a next-stage for crushing orsmashing again.